Kiln



May 23, 1933- H. M. ROBERTSON KILN Filed Nov. 17, 1928 5 Sheets-Sheet l May 23, 1933. H. M ROBERTSON KILN Filed Nov. 17, 1928 5 Sheets-Sheet 2 NVENTOR lllffoberl'solv.

ATTORNEY 5 Sheets-Sheet 3 KILN H. M. ROBERTSON Filed Nov.

INVENTQR ff, M.Kober5 on` ATTORNEY May 23, 1933.- H. M. ROBERTSON KILN Filed Nov, 17, 1928 5 Sheets-Sheet 4 INVENTOR //V. Robe rivaon.

ATTORNEY May 23, 1933. H. M. ROBERTSON 1,911,089

ATTCRNEY Patented May 23, 1933 UNITED STATES HARRY MAGRUDER ROBERTSON, OF CLEVELAND, OI-IIO Kinn Application filed November 1?', B528.

This invention relates to apparatus for burning, firing or heat treating ware of varions kinds formed from clay or metal; more particularly it relates to a kiln of the tunnel type through which the ware is moved while being treated.

One object of the invention is to provide an improved kiln having means disposed outside the kiln for supporting and conveying the ware to be treated within and through the kiln.

Another object of the invention is to provide an improved kiln and improved ware Carrying supports feo-operable therewith, both so constructed that in the conveying of the ware through the kiln the ware is within the kiln but the bodies or frames of the carrying supports and their supporting wheels are exterior to the kiln.

Another object of the invention is to provide an improved tunnel kiln so constructed and related to the ware carrying supports that all provision for cooling the latter is eliminated.

Another object of the invention is to construct a kiln of the muflie type wherein the ware to he treated is subjected to heat and a cooling medium while being maintained out of Contact with the products of combustion and cooling medium.

Another object of the invention is to construct an improved tunnel kiln wherein heating and cooling is effected by radiation and provision is made at one or more points to prevent drift of the atmosphere within the kiln.

Another object of the invention is to construct a kiln which is relatively simple and has a large capacity.

Another object of the invention is to profide an improved ware carrying support so constructed that only that portion thereof which supports the ware is within the kiln while it is being moved from end to end thereof.

Serial No. 320,175.

A further object is to provide animproved ware carrying support having a refractory portion adapted to removably carry the ware carryin g member.

Other objects of the invention will be apparent to those skilled in the art to which my invention r lates from the following description taken in connection with the accompanying drawings7 wherein Figs. l and la illustrate in plan a kiln embodying my invention.

F 2 and 2a, are vertical sections substantially on the lines 2 2 and 2& 250 of Figs. l and la., respectively.

Figs. 3 and 3a, illustrate in side elevation the kiln; the support moving mechanism being omitted.

Fig. 4 is a section on the line 4 4 of Fig. 2a.

Fig. 5 is a section partly on the line 5 5 of Fig. 2 and partly on the line 5& 5a of Fig. 2a.

Fig. 6 is a section on the line 6 5 of Fig.

Figs. 7 and 8 are sections on the lines 7 7 and 8 8, respectively, of Fig. 2a.

Fig. 9 is a. fragmentary section on the line 9 9 of Fig. la.

Fig. 10 is an end view of a ware carrying support and ware supporting member.

Fig. 11 is a side View of the support and ware supporting member.

Fig. l2 is a plan view of the ware carrying support.

Fig. 13 is a plan view of the ware carrying support with the ware supporting member partly loaded with ware.

In the drawings, the kiln consists of a unitary structure wherein is incorporated a heating and oxidizing portion l and a cooling portion 2, said portions having contiguous chambers or channels 1w, 2a, respectively, through which the ware passes to be heated and oxidized and then cooled.

lThe Ware herein shown is ordinarily known as matte glazed tile indicated at A, but it will be understood that other kinds of ware formed of ceramic material or metal may be operated upon or treated. The kiln is shown with heating and cooling chambers or channels 1a, 2a, having an area in cross section large enough for ware such as shown. lVhere the ware is larger or arranged in multiple courses, the area of these chambers'l is increased. In the preferred form of construction, as illustrated herein, the heating of the ware is effected by radiation, so that an oxidizing atmosphere results in the heating chamber 1a, but by admitting all or a. portion of the products of combustion into said chamber, in the manner hereinafter set forth, a reducing atmosphere may be provided therein.

indicates the side walls of the heating and cooling portions and 6 indicates the bottom wall thereof. The side walls are formed of suitable refractory blocks or bricks 5a and those portions of the side walls forming the sides of the heating portion 1 and main heating section 3 are provided with an outer insulation of suitable material indicated at 5b. The bottom 6 is formed of suitable refractory slabs or bricks, an intermediate portion 6a being formed of an insulation material. The upper portions of the side walls 5 support abutments or caps 7, 7, having inclined faces on which rests an arch member 8. The abutments 7 are held in place by longitudinally extending members 9, which are incorporated in the side walls 5 and supported partly thereby and partly by angles 10, secured tothe side plates 11 of a steel shell 12. The arch members 8 for the heating portion 1 and main cooling section 8 are covered with insulation material 13. The side walls 5 may extend below the bottom 6 to support the portions 1 and 2 on the foundation A or other bed, but by preference these portions are rigidly supported by a frame-work 14 above the foundation to position the bottom 6 above and spaced from tracks 15 on which wheeled supports 16 run,` as will later appear. The framework 14 preferably consists of cross members (such as I-beams) 17 forming ties for the tracks 15, uprights 18 secured at their lower ends to the ties and at their upper ends to the bottom plates of the shell 12 by angles 19 and uprights 20, connected at their lower ends to the ties 17 by angles 21, the uprights 20 being spaced so that they lie outside of but close against the side walls 5 to brace the heating and cooling portions 1, 2, against lateral movement. The uprights 2O` may be connected at their upper ends by ties 22, which may be tightened to clamp the uprights 20 against the sides 5.

The inner opposing faces of the side walls 5 for the heating portion 1 and main heating section 3 are provided with longitudinally extending shelves 23 on which rest arch members 24, 25, formed of a material which has a relatively high co-efticient of heat conductivity, so that heat in the heating portion 1 will be readily conducted through it and heat the ware by radiation and likewise the heat radiated from the ware in the main cooling section will be readily conducted through the arch member 25 and become absorbed by the air thereabove, as will later appear. The arch member 24 co-operates with the side walls 5 and adjacent arch member 8 to provide above it a muflle 26 through which the products of combustion flow, such inutile being closed at its inner end by a wall 26a and atiits outer end by a wall 27 and such arch member co-operates with the side walls 5 and bottom wall 6 of the heating portion 1 to provide below it the oxidizing or heating chamber 1a, already referred to.

rllie arch member 25 co-operates with the side walls of the main cooling section 3 and adjacent arch 8 to provide above it a cooling muttle 28 through which air ['lows as will later appear, such inutile being closed at its inner end by a wall 29 and at its outer end by a wall 30; and such' arch member co-operates with the side walls 5 and bottom 6 of the cooling section 2a to provide below it the cooling chamber 2a, already referred to.

3l indicates an opening or way formed in the bottom 6 and extending from end to end of the kiln, that is, from its inlet end to its outlet end. This opening 31 is arranged centrally of the bottom or midway between the side walls 5, 5, and provides the bottom sections 6a, 6a, extending inwardly from these walls. [as will be noted from Figs. 4, 5, 6, 7 and 8 the width of the opening or way 31 is sutlicient to accommodate the upright sections 16a of the carrying supports 16, permitting the section 16a to move between the opposed faces of the bottom sections 6a, 6a., without engaging therewith.

The heat supply means, indicated at 32, for the inutile 26 is preferably arranged at the inner end thereof in the wall 26a and it may comprises one or more suitable nozzles 32a for burning oil or gas. I preferably A provide two nozzles 32m controlled by valves 33 and connected to a supply pipe 34, the nozzles 32a being in operative relation to the burner ports 26a formed in the wall 26a.. 35 indicates an exhaust port adjacent the outer end of the mull'le 26, this port being connected to a discharge conduit 36, which leads to the inlet of a suction device 87, such as a fan mounted within a suitable casing 87 and driven by a motor 38. As will be -v understood, the suction device tends to create a vacuum within or at the outer end of the inutile 26, the effect of which is to suck or draw the products of combustion through the muffle in a rapid manner over the surface of the arch member 24, whereby the latter may absorb a relatively large percentage of the heat units in the heated gases and products of combustion, and radiate such heat onto the ware as it moves through the chamber 1a.

39 indicates auxiliary mulfles mounted within the bottom sections 6a and serving to heat the bottom sections 6a whereby heat will be radiated from the latter, from points below the ware supporting members 40. Each auxiliary muftle 39 is located in one of the bottom sections 6a and extends longitudinally thereof substantially from end to end of the heating portion 1.

The inner ends of the auxiliary munies 39 are connected with the mufie 26, by iues 41, formed in the side walls 5, as shown in F ig. 5. The outer end of each muliie 39 has one or more (preferably three) discharge ports 42 each connected by conduits 43, 44 and 45 with the inlet side of the suction means 37, the conduit 45 being shown connected to the conduit 36 (Fio. 1). Each conduit 43 is provided with a damper or valve 46 to regulate t-he discharge through it. By proper adjustment of the valves 46, a portion of the products of combustion in the muille 26 will be drawn through the flues 41 andmufies 39 to heat the bottom sections 6a throughout their lengths so that the heat absorbed by them will be radiated into the channel 1a.

For the purpose of providing a reducing atmosphere in the channel 1a, as may be desired for certain kinds of ware, I connect to the discharge side of the suction means 37 a pipe 47 which has one or more branches 48 leading through the adjacent side wall 5 into the channel 1a, preferably near the inner end thereof, whereby the products of combustion or a portion thereof will be forced into the channel 1a. Suitable valves or dampers 49, 50, are provided for regulating the ow of the products of combustion to the pipe 47 and to the exhaust or chimney 51. Each branch pipe 48 is also provided with a valve or damper 52. The branches 48 preferably have their discharge ends leading into that portion of the channel that is adjacent or below the hottest portion of the muflie 26.

The main cooling chamber 3 is substantially similar in construction to the heating portion 1, except that that end (its outer end) toward which the ware carrying supports 16 move has an air inlet connected to and receiving air from a manifold, 53 and its opposite or inner end is formed with a discharge outlet or port 54, such port being preferably formed in the adjacent roof 8 and connected with a riser 55 leading to a suitable discharge.

As clearly shown in Fig. 7, the side walls 5 extending along the secondary heating section 4 receive between them the manifold 53, the latter being supported on the shelves 23. At its outer end one wall (for example the upper wall) of the manifold is formed with an inlet port 56, to which is connected a conduit 57 leading from the discharge side of a blower 58 driven by a suitable motor 59. The blower 58 serves to set up a current of air into and through the manifold 53, muiiie 28 and outlet 55. The outlet 55 may have connected to it a suction creating means to increase the rate of iiow of the air through the manifold 53 and muiile 28. he air flowing through these chambers serves to rapidly absorb heat from the ware, whereby it is uniformly cooled to a low enough temperature to permit the ware to be discharged at the outlet lend of the kiln in the time interval for each load to reach the outlet.

I preferably provide at one or more points throughout the channels 1a, 2a, means for preventing a relatively large or undue drift of air horizontally through these channels, the obj ect being to keep the air in these channels stationary, or substantially so that by controlling the supply of heat and its iow through the mulile 26 and supply and flow of the air through the manifold 53 and muffle 28, predetermined heating and cooling temperatures may be attained and effective and etiicient treatment of the ware insured while the latter is moving through the kiln in a predetermined period of time. in the present construction the means for preventing drift of the air or annosphere through the channels 1a, 2a, consist of one or more fiat arch members. ln the preferred construction, as shown, I provide an arch meinber 60 at the inlet end of the kiln to prevent an undue amount of outside air entering the channel 1a, another member' 61 between the contiguous ends of the channels 1a, 2a., and another member 62 betw en Athe contiguous ends of the cooling sections 3, 4. Th arch members 69, 61, 62, rest on the shelves but being flat or horizontal they lie in close relation to the upper surfaces of the ware and thus prevent drift of the atmosphere, as already set forth. By positioning the members 60, 61, 62, in the locations described, danger of the atmosphere in the channel 1a which has a high temperature, from mixing with the atmosphere in the channel 2a is avoided and danger of the atmosphere in the channel 2a below the inutile 28, which atmosphere has a higher temperature than the atmosphere in the remaining portion of the channel 2a, mixing with the atmosphere in this latter portion of the channel 2a, is overcome.

The carriers or ware carrying supports 16 are of special construction so that they may be movably supported exteriorly of the kiln while supporting the ware within the kiln and moving it therethrough for treatment. Each support comprises a frame 16 mounted on wheels 16?) and a refractory member 16a, already referred to. The frame 16 may consist of a body portion 63 and depending axle carrying sections 64, 64, each carrying an axle for the adjacent pair of wheels 16?). he body portion 63 is preferably U-shaped in cross section from end to end to form a seat for the lower portion of the refractory member 16a. rlhe refractory member 16a is of a width to extend through the longitudinally extending opening` or way 31 to support the support-ing member 40 within the channels 1a, 2c, and above the bottom 6 and to move longitudinally of the opening without engaging the bottom sections 6a. The ware supporting member 40 removably rests on the refractory member 16a and extends to either side thereof and overlaps the spaces between the refractory member and opposed faces of the bottom secn tions 6a. The refractory member 16a and the support lt), are preferably interlocked one relative to 'the other, to provide a guide for the operative when positioning a support 4:0 on the refractory member 16a and to prevent the latter from being readily dislocated. Th interlocking means may comprise a rib 65, preferably having tapered sides, provided on the under face of the support 40 and centrally thereof and a complementary groove or recess 66 formed in and extending longitudinally and centrally of the upper edge or face of the refractory member, the portions of this face at either side of the groove 66 being engaged by the support 40 and forming a suitable base therefor. By making the ware supports 4() removable, they may be loaded at any desired station and conveyed to another station, for example the inlet ends of the kiln for mounting on the ware carrying supports 16; likewise at the discharge end of the kiln the supports LLO while ioaded, may be removed from the :arrying supports 16 and conveyed to any desired point. rllhe upper face of each support 46 is provided with spurs or supporting sevices 67 extending upwardly a short distance. The ware A rests on these devices and spaces them from the upper face of the support a suilicient distance to al low air to circulate underneath the ware and facilitates the handling of the ware in placing it on. and removing it from the support.

Each ware carrying support 16, after being loaded, is moved into the kiln channel 1a by a thrust member 68. Each support in being moved into the channel engages with the support previously moved thereinto and moves it toward the outlet end of the kiln a distance equal to the stroke of the thrust member. As the supports engage end to end (see Figs. 2, 2a.), the moving of loaded supports into the kiln channel successively at predetermined intervals will result in step by step moving them all through the kiln in a predetermined period of time.

The thrust member 68 may comprise a rack slidable in a frame 69 and in mesh with a pinion 70 and guided thereby and a roller 71. The pinion 70 is fixed to a shaft 72 mounted in bearings 73. The shaft 72 has fixed to it a worm gear within the gear casing 74 and this worm gear is in mesh with a worm fixed to a shaft 75 which is driven by a motor 76. The motor 76 is reversible so as to reciprocate the thrust member 68, whereby it may be retrieved to pfermit a support 16 to be positioned in front o it.

Figs. 1, la, 2, 2a, 3 and 3a show the kiln in operation and completely filled, the carrying supports 16 extending from end to end of the kiln (ware being shown on one supporting member 40 only to simplify the illustration); and Figs. 1, and 2 show the feeding or moving mechanism operating to move a support into the opening 31 and the remaining supports forwardly one step.

In moving outwardly beyond the secondary cooling section 4, each support is pushed on to a transfer truck 77 mounted on tracks 78 in a sub-way 79. The truck 77 is then moved into operative relation to return tracks 80, whereupon the support 16 is moved olf the truck 77 onto the tracks 80, a moving mechanism 81, preferably similar to the mechanism used to move the sup ports through the opening 31, being provided. The mechanism 81 operates through each support 16 to move the preceding supports 16 along the track 80, from which each support is pushed onto another truck 82 mounted in a sub-way 83. rlhe ruck 82 is then used to position each support at the inlet end of the kiln. The ware supporting members 40 may be loaded with ware A and then positioned on the refractory members 16m or such members may be positioned first and then loaded; also the ware A may be removed from the members l0 without removing the latter from the supports 16 or such members may be first removed from the supports. These operations may be carried on at any desired station or stations.

In the drawings I have shown but one course of ware A on each carrying support 16, but by increasing the height of the channels l, 2e, and using shelves or setter plates on each supporting member 40, a plurality of courses of ware on each support 16 may be conveyed through the kiln.

In my construction of kiln I provide heating and cooling mufiles for the ware, the ware being subjected to direct radiant heat in the heating portion and radiating heat direct to the cooling inutiles in the cooling portion. My construct-ion is advantageous as it has large capacity and the Ware can be treated in approximately three hoursas compared to other kilns of which I have knowledge requiring from forty to sixty hours time to effect firing and coolling of the Ware. Another advantage re-l sides in the mounting of the Ware upon movable supports such manner that the supports are supported and guided exteriorly of the kiln but have a refractory portion that extends into the kiln to support the Ware therein and to convey it therethrough. This arrangement insures dur ability of the supports and their tracks, permits the supports to be ot relatively cheap construction, simplifies the kiln construction and eliminates the necessity of providing a cooling means for the supports and their tracks. It Will be noted that the members on Which the Ware is supported, are

movable from the supports 16. rIhis permits these mem ers to be loaded at some distant station and transported to the inlet end of the kiln Where they are positioned on the supports 16 and to then be disengaged from the supports at the outlet end oi' the kiln and transported to a place of storage.

To those skilled in the artto which my invention relates many changes in construction and Widely differing embodiments and applications of my invention Will suggest themselves Without departing from the spirit and scope thereof. My disclosures and the description herein are purely illustra- -tive and are not intended to be in any sense limiting.

What I claim is: 1. In a tunnel kiln for heating Ware comprising a` channel through Which the Ware moves, one Wall of the channel having an opening extending longitudinally from end to end of the channel and adapted to permit portions of Ware carrying supports to extend through it and support the ware Within the channel While traversing the opening, a muiiie Within and extending longitudinally of the Wall in which said opening is formed, means for supplying heat into one end of said muiiie, suction means connected to said muflie, and means in operative relation to said opening and exterior to the Walls of the channel Jfor movably supporting the Ware carrying supports.

2. In apparatus of the class described,

vthe combination of a heating portion and a cooling portion having contiguous channels, the bottoms of said channels being formed with longitudinally extending aligned openings, mutHes Within and extending longitudinally ot the bottom Walls of the heating portion at either` side of the opening therein, means for supplying heat to the channel in said heating portion and each of said muiiles, guide means exterior of said Aheating and cooling portions, and supports for Ware guide means and arranged to support the Ware Within said channels and each having a portion extending through and movable endWise of said openings and move the saine therethrough.

3. In apparatus of the class described, the ceinbinaticn ot a heating portion and a cooling portion each having an arch member supported by its side Walls to form a channel for the Ware to be treated and a muitle above the channel, combustion means at one end of the muitle. in said heating portion, suction means at the other end of the muil'le in said heating portion serving to draW the products of combustion through said mule, and means for causing a flow of air through the inutile in said cooling section.

4l. In apparatus of the class described, the combination of a heating portion and a cooling portion each havingan arch member supported by its side Walls to form a channel for the Ware to be treated and a muiiie above the channel, combustion means at one end of the muffle in said heating portion, suction means at the other end of the inutile in said heating portion serving to draw the products of combustion through said muffle, and means for causing` a flow of air through the muiie in said cooling section, Iin a direction opposite to the direction of travel ot theware.

5. In apparatus of the class described, the combination of a heating portion and a cooling portion each having an arch member supported by its side Walls to form a channel for the Ware to be treated and a muflie above the channel, combustion means at one end of the muflie in said heating portion, suction neans at the other end of the muil'le Ain said heating portion serving to oravv the products of combustion through said muille, and means for causing a loW of air through the muiile in said cooling section, and a conduit leading from the outlet for said suction means for discharging products of combustion into the Ware channel in said heating portion.

6. In apparatus of the class described, the combination ot' a heating portion and a cooling portion, an arch member in said heating portion supported by the sides thereof to form a channel for the Ware to be treated and muftle above the channel, an auxiliary muiiie formed in and extending' longitudinally of the bottom of said Ware channel and connected at one end to irst mentioned inutile, combustion means at that end of the first mentionedY muiile to which the auxiliary inutile is connected, and suction means connected to the respective opposite ends of said mues.

7. In apparatus of the class described, the combination ot a heating portion and a cooln ing portion each having an arch member supported by its sidewalls to form a channel for the ware to be treated and a niutle above the channel, an auxiliary mutile formed in and extending longitudinally of the bottom of the ware channel in said heating portion and connected at its inner end to the inner end of said first mentioned mut fle, combustion means at the inner end ot' said first mentioned muile, and suction means connected to the outer ends of said inutiles.

8. In apparatus of the class described, the combination of a heating portion and a cooling portion each having an arch member supported by its side walls to form a channel Jfor the ware to be treated and a inutile above the channel, an auxiliary mullle i'ormed in and extending longitudinally of the bottom of the ware channel in said heating portion and connected at its inner end to the inner end of said first mentioned muflle, combustion means at the inner end of said first mentioned muflle, and suction means connected to the outer ends of said inutiles, and a valved conduit leading from the outlet for said suction means to said ware channel for discharging products of combustion thereinto.

9. In a tunnel kiln for heating ware comprising a. chamber and a channel through which the ware moves below said chamber, the bottom of the channel heilig formed midway between its sides with an opening extending longitudinally from end to end of the channel and providing bottom sections at either side of the opening, combustion means at one end of said chamber, muiie extending through one of said bottom sections and connected at one end to said chamber, and suction means connected to the respective opposite ends of said chamber and said muflle.

l0. In a tunnel kiln for heating ware comprising a chamber and a channel through which the ware moves below said chamber,

the bottom of the channel being formed midway between its sides with an opening extending longitudinally from end to end of the channel and providing bottom sections at either side of the opening, combustion means at one end of said chamber, a muffle extending through one of said bottom sections and connected to said chamber at that end adjacent to said combustion means, suction means connected to the opposite end of said chamber, and a valved connection between the opposite end of said muie and said suction means.

ll. In apparatus of the class described, the combination of a heating portion and a cooling portion having contiguous channels for ware, a. mullle for each said portion, the bottom wall of each said muflie forming the top for the channel of the adjacent portion, said muflles having inner end walls disposed in spaced relation, and a horizontal 

